Skip to main content

Reopening of L-type calcium channels in human ventricular myocytes during applied epicardial action potentials

Buy Article:

$43.00 plus tax (Refund Policy)

Abstract Aims: 

Present study was performed to compare the dynamics of human L-type calcium current (ICa,L) flowing during rectangular voltage pulses, voltage ramps, and action potentials (APs) recorded from epicardiac and endocardiac canine ventricular cells. Methods: 

ICa,L was recorded in single myocytes isolated from undiseased human hearts using the whole cell voltage clamp technique. Results: 

The decay of ICa,L was monotonic when using rectangular pulses or endocardial APs as voltage commands, whereas the current became double-peaked (displaying a second rise and fall) during epicardial (EPI) APs or voltage ramps used to mimic EPI APs. These ICa,L profiles were associated with single-hooked and double-hooked phase-plane trajectories, respectively. No sustained current was observed during the AP commands. Kinetics of deactivation and recovery from inactivation of human ICa,L were determined using twin-pulse voltage protocols and voltage ramps, and the results were similar to those obtained previously in canine cells under identical experimental conditions. Conclusions: 

ICa,L can inactivate partially before and deactivate during the phase-1 repolarization of the epicardiac AP, and reopening of these channels seems to be associated with formation of the dome.
No References
No Citations
No Supplementary Data
No Data/Media
No Metrics

Keywords: action potential; calcium current; human myocytes; regional differences; voltage clamp

Document Type: Research Article

Affiliations: 1:  Department of Physiology, University Medical School of Debrecen, Debrecen, Hungary 2:  Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary

Publication date: 2004-01-01

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more